Primer - Anchoring Framing to Foundation

Hey folks, thanks so much for continuing to visit this blog, even though my activities have been 100% occupied with building theEnclosure.ca and the last article I posted here was all the way back in February. As promised, I intend to post more technical themed articles to this blog and use the project journal on my build site for my day to day thoughts and tribulations on building an energy efficient home.

So, it is time for an article that provides a primer into Anchor Bolts. In the days of old, a concrete placing crew would just embed a 1/2" anchor every 4ft or so and call it a day.


Most dwellings had either small cripple walls placed above the foundation wall or had the floor joist assembly sitting right on top of the sill plate. Both of these were able to easily accommodate the location of the anchor bolt with little effort.


Modern construction has changed a great deal in this regard. In areas of high seismic activity, the location of anchor bolts is critical to meet either the code prescriptive path to seismic rigidity, or an engineered path. For us @ theEnclosure.ca, we were forced by the Municipality to upgrade from the Building Code prescriptive path and instead use the prescriptive path laid out in Canadian Wood Council's Engineering Guide For Wood Frame Construction Part C.


In Part C, the requirements for anchor bolts for my region (Lower Mainland BC, Canada) are laid out as follows:

- There must be two bolts minimum per braced wall (seismic) panel

- The bolts must be installed no more than 1.64 ft from each end of a foundation wall

- Bolts must be installed every 7'10"

- 1/2" embedded 4" into the concrete


It is interesting, in contrast, the BC Building Code required 1/2" anchor bolts spaced no more than 5'6" apart (7'10" was allowed but only for 5/8" bolts).

So now, it is critical that prior to your concrete crew coming, all anchor bolt locations are marked out on the form work to comply with the newer seismic regulations. It is also important that the setback from the foundation wall face is identified to ensure that the anchor bolt will miss objects like rimboards (engineered wood) or rim joists (real wood).


For our construction, we had an added level of difficulty surrounding the placement of these bolts. Our design includes a dropped floor assembly that is flush with outside grade in order to meet the requirements of SAFERHome Society. But code still requires that the foundation project 6" above grade (BCBC 9.15.4.6) which results in a concrete foundation stub projecting above the floor surface.

Building code requires the foundation to extend 6" above grade to prevent wood components from rotting.  On a floor assembly that is flush with grade (dropped), this results in a concrete stub extending above the floor.

As my wall framing was then mounted directly to the foundation, it was critical that in addition to meeting the seismic requirements, I also had to ensure that they were placed to miss my wall stud framing. I was about 85% successful in this endeavour. The rest had to be cut off and replaced with drill-in anchors, which my inspector stated would accept for a limited qty.


SO, you have all your anchor bolts embedded at the right locations, lets add the washer and nut and call it a day - right? From a code perspective, you would be right. But there is a best practice when it comes to anchor bolts. I have to thank one of my Home Inspection client's Nikolas for this information.


Turns out that the washer makes a perfect wedge to split the plate apart during an earthquake as the bolt bends under the shear loads exerted by a quake. Who knew??? I reviewed the article that Nikolas sent and written by Howard Cook titled "The importance of Plate Washers"


Howard retrieved the following graph from the Los Angeles Building and Safety department (a group that knows a little bit about earth quakes don't you think!)

You will see that at every point along the graph, that the wall using a plate washer deflected less for a given force when compared to the round cut washer. By introducing a 3" x 3" plate, you are able to better prevent the bolt from bending under shear and preventing the splitting of the sill plate. The mentioned article includes a sketch by Nels Roselund that shows the reactions involved.

Based on this information, we elected to use the 3"x3" plates on The Enclosure but did run into problems on many of the bolt locations. Unless the anchor bolt was dead centre in the 2x4 sill plate, there was not enough room between the sheathing and the bolt or the inside face of the stud and the bolt, to place the plate. SO we used the plates for as many of the bolts as possible and then just the standard washers for the rest.

Just enough room for plate between bolt and sheathing

This bolt was placed too far outboard to slide the plate on.

Howard has also published an article titled Bolting: Attachment Of The Mudsill To The Foundation for those interested in additional reading. Nikolas also forwarded the article QuakeCheck: When the big one comes, will your home be "Safe enough to stay?" which made for a great read to further brush up on this subject and how to address it.


If you have an older home, it may be time to upgrade your anchorage. Is it not worth a few hundred dollars and one day of your weekend to make your family as safe as possible in a seismic event?


Thanks for visiting!

Rotting OSB - Why I refuse to perform rough-in construction during the winter!

I regularly go by a construction site where a friend of my neighbor is the G.C.   This house in out by the ferry terminal in West Vancouver and when done will be a very high cost home.

My latest visit reminded me of why I really do not want to expose my build to the winter rains.  In fact, I will try to keep all rain of the structure until closed in by installing a 60ft x 100ft tarp over a metal cable strung between two large trees.

But back to the visit, I have been visiting this property since before the old house got taken down, and in fact this is where I salvaged very nice cabinetry to use in the walk in closet, master bath, and family entrance as well as a new wall oven and a like new drawer dishwasher.  I also was able to salvage a lot of plant material from the property but so much more got left behind with the thinking it was out of the way, when in reality - they have just been trashed, such a shame.

Cabinet salvaged to be used in Master Bath

Gorgeous drawers and storage for Master Walk-In-Closet

Base cabinets to be used for family entrance

Wall cabinets to be used for family entrance

 But again I digress.  The new house has been under construction since the middle of May 2013.  The roof was installed sometime in December, but as of yesterday the majority of windows still have not been placed, and as the main floor living areas is 100% windows, the structure is very much NOT waterproof and has been subjected to many storm events leading to total saturation.  And the structure is starting to show its distress accordingly.  I noticed these symptoms a couple of weeks ago when there but was only able to return with a camera yesterday.

This dwelling is still at the rough in stage and is showing rather significant surface mould and rot fungi.  These OSB webs are now compromised **A conversation with someone much smarter than me indicated the webs should still be OK as long as this is dried out and cleaned off **.  Not only do I want to prevent this wetting with a tarped site, this is a perfect example of how poorly OSB stands up in wet environments.

 In the end, this will probably get cleaned up as the G.C. is quite conscientious, but normally, this would just get closed in and the occupants would wonder why their floors bounce a little more than they should.

Updated - Plumbing Design Complete - Not for the impatient!

Click here to view Completed 3D Plumbing Design - Updated

I plan on installing my own plumbing system in this house and am quite comfortable working with pipe.  However it had been several years since I had reviewed the plumbing codes and my memory from those days indicates there were a lot of rules regarding the sizing and routing of pipes!  So instead of talking the time to read and re-learn the code, I decided to contract out this part of the design.  I contacted an instructor of a BCIT 'Build your own house' course I had taken a few years back who provided the contact info for his son, a licensed plumber.

Richard Pugh  www.rpplumbing.ca 604-351-9145  Richard.pugh@rpplumbing.ca

I sent Richard off a set of preliminary drawings and asked if he could provide a plumbing isometric.  Now anyone who knows the plumbing business will understand that this is a strange request for a plumber and I was met with the expected hesitation.  Most residential plumbers do not draw out the system they install, and instead just complete a very rough plan, after the framing is complete, to allow for material ordering.  They then 'flesh' out the system as they are on site installing it.

If the designer (specifically those responsible for structural) has not taken into account the plumbing system, the plumber is left with some creative ways to route the pipes - especially the horizontal offsets and horizontal branch drains. And in some cases, with some plumbers that follow poorer practices, structure is modified to make room for the plumbing, compromising the stability of the structure (this seems to be rampant in the home renovation industry). In this conversation, it is important to remember that plumbers work in the world of 90º, 45º, and 22.5º fittings and all lines have to slope to drain.  If you have ever laid out a plumbing system, these constraints become front and center quite quickly and dramatically effect the routing of the pipes.

After a week or so, I met with Richard and went over his drawing markups. They identified the line routings and sizes and included key information like max change in direction between a water closet and its vent (225º) as well as the max distance between a WC flange and its vent (3m).  Everything looked great during our meeting review and I set off back to the office to fully flesh this plan out in my mind.

I have been using a program called Home Designer Pro to model the house in 3D and also create the plan views.  Unfortunately, this program does not include the functionality to add in plumbing.  So my Google search turned up a program called Quick Plumb (http://www.quickplumb.com/).  It had a 30 day free trial and a by month subscription after that.  The program showed a lot of promise, so I downloaded and started to model the layout that Richard had provided.  The program while easy to use on the surface, did have considerable challenges and only perseverance and patience provided a completed 3D plumbing model (I will give a full review of Quick Plumb at a later time).

Very quickly while starting the 3D modeling, I was able to see that some of what Richard had provided was not going to work, and I realized how difficult it is for plumbers to visualize a dwelling when only provided standard 2D floor plans.  The architectural 2D plans often provided do not typically identify the structural details like floor beams.  It is also difficult to visualize the alignment of each floor without a lot of measuring or being given some form of 3D model.

I unfortunately had not completed the structure at the time I had Richard start on the project so could not give him the structural drawings showing final beam placements. And I had no easy way to provide the Home Designer Pro 3D model to others.  So we had beams in the way of branches and stacks going through cavities reserved for pocket doors and similar interferences.  The pipe layout as drawn was just not going to happen.

SO I utilized the sizing and 'rules' presented in Richard's markup and set out to alter the layout to fit my structure.  In the end, I had to drop three beams in the basement (my beams are generally flush so concealed within the floor cavities) and re-space some floor trusses.  Fortunately, these beams could be dropped into either wall assemblies below, or into rooms that I did not mind having lower ceilings (like bathroom and sauna shower room in basement).  I also had to dramatically reroute the plumbing venting as I just did not have enough space in the floor assemblies for the drains AND vents to pass over each other (my cavities are 11-7/8" deep).

Richard still has to check over the resultant design, but I believe it is quite close to what I will end up with.  A 3D 'spin' of the design is available on my YouTube channel http://youtu.be/2aElBPP5Ryo.

Update: Richard went through and essentially 'approved' the plan.  I have updated the 3D spin to show the model now that I have also added in the required clean-outs.  The model still contains a code error (it was just too difficult to edit in the program). Can you spot it?

The design meets the following considerations:

•  Basement will drain to a sump and then 'pump up' to the building drain that gravity drains to the Municipal sewer (note this is not how it is drawn. The software does not have functionality that allows for a pump up)
• Upper two floors to gravity drain to Municipal sewer. 
• Upper floor grey water lines will pass through a heat recovery device before exiting the building.
• Toilets will drain separately from the rest of the system to accommodate a future grey water heat recover system upgrade and possible grey water filtering system to allow it to be reused in toilets.

As always - thanks for reading and I look forward to any comments you may have.

Thinking Ahead Saves Money!

I was notified about 6 months ago, that the District would be replacing the water line along our street.  As I was building next year, I saw an opportunity to both relocate the curb-stop so that it would not be under the new location where I intend to run our driveway, and increase the size of line in case I decide to put in a fire suppression system.

When I first approached the District, I was quoted the standard cost of $4500 to put in a new service at the start of new construction (I suspect they make everybody replace the service right back to the main, as a service from a torn down dwelling is most likely past its designed service life).  Fortunately, reasonable heads prevailed once I pushed back a little, and the price dropped to $350, representing the material cost difference between the ¾” they planned on installing and the size I needed.  I jumped at this and went down to the hall and paid my bill.

Well over the last couple of weeks, the project has been completed. Thanks to the District crew who did a great job!

Replacing the main – work went quickly as there were very few interference's.  The next length to add will be ‘mine’.

Bringing over the main that includes my service connection.

Now that is going to move some water!  I believe this is a 1.5” line, but have to admit, I did not check the size.  It will be a surprise next spring when I dig up the curb-stop to connect my new line to.

Main installed and waiting for the second pass when they do the service hook-ups.

New Service connected and run to curb-stop. If you look closely, you will see Alfie in the background, who helped me dig the trench to tie from the new curb-spot location to the existing one.

Getting ready to back-fill the trench.

Connecting the Curb-Stop while back filling the trench is continuing just behind.  The team ran like a well choreographed ballet.  No wasted time here!

These fittings were big and needed some extra hands to tighten.  I used Alfie to pre-dig the tie-in trench and around the curb-stop so the crew did not have to worry about my water and electrical conduit.

Ready for the next day, when the crew kindly agreed to tie over to my existing service (something I originally was responsible for).

Now tied into my old service to the house (will be abandoned when the new house is built).  You can see the cut-off pipe from the old curb-stop at the top right quadrant of the photo.

New curb-stop reduced to ¾” in order to temporarily tie over to my existing service.

3/4" Tie in to old service complete and ready for back-fill.

Project generally complete after Alfie helps fill in the trench on my side of the curb stop.

Sure is nice to have your own excavator!